Liquid applicator

ABSTRACT

Liquid applicators are described. The applicators ( 100 ) include a lever ( 130 ) having a hinge ( 132 ), grip ( 134 ) and foot ( 136 ) integrally formed with a hollow body suitable for receiving a liquid-filled ampoule. The foot is positioned adjacent the ampoule and crushes the ampoule when the lever is depressed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 61/880,472, filed Sep. 20, 2013, the disclosure of which is incorporated by reference in its entirety herein.

FIELD

The present disclosure relates to a liquid applicator for applying a liquid to a surface, e.g., a surgical prep applicator. In particular, the present disclosure relates to a liquid applicator having a lever suitable for crushing an ampoule and releasing liquid within the applicator.

SUMMARY

Briefly, in one aspect, the present disclosure provides a liquid applicator for applying a liquid to a surface. Generally, the applicator comprises an elongated hollow body comprising a wall defining an internal chamber having a closed end and an open end; wherein the wall comprises a handle region and a crush region and wherein the ratio of thickness of the wall in the crush region over the thickness of the wall in the handle region is less than 1. A first ampoule formed of a frangible material is located in the internal chamber proximate the crush region and containing the liquid. A lever is integral with the hollow body and comprises a hinge projecting from a first location attached to the hollow body to a second location, a grip extending from the second location to a third location, and a foot integral to the wall adjacent the crush region. The lever comprises a first truss extending from the third location to the foot; a second truss extending from the second location to the foot, and a brace connecting the hinge and the second truss. The width of the first truss is tapered from a first width proximate the third location and a second width proximate foot; wherein the ratio of the second width over the first width is less than 1.

In some embodiments, the width of the second truss is tapered from a third width proximate the second location to a fourth width proximate the foot; wherein the ratio of the fourth width over the third width is less than 1. In some embodiments, the brace is substantially parallel to the major axis of the elongated hollow body.

The above summary of the present disclosure is not intended to describe each embodiment of the present invention. The details of one or more embodiments of the invention are also set forth in the description below. Other features, objects, and advantages of the invention will be apparent from the description and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a side view of one exemplary liquid applicator according to some embodiments of the present disclosure.

FIG. 2 illustrates a cross section of the exemplary liquid applicator of FIG. 1.

FIG. 3 illustrates a side view of one exemplary lever corresponding to the lever of the exemplary liquid applicator of FIG. 1.

FIG. 4a illustrates a cross section of the exemplary lever of FIG. 3, before crushing.

FIG. 4b illustrates a cross section of the exemplary lever of FIG. 3, after crushing.

FIG. 5 illustrates an end view of the exemplary lever of FIG. 3.

FIG. 6a illustrates another exemplary lever according to some embodiments of the present disclosure.

FIG. 6b illustrates yet another exemplary lever according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

Antiseptic preparation of patient's skin for surgery conventionally includes a 3-10 minute scrubbing of the affected area with an antiseptic soap solution followed by the application of a water-soluble antiseptic paint solution. These solutions have been applied with saturated sponges that are attached to a blade or held with forceps. These sponges are often saturated by soaking them in open pans of solution. While inexpensive, these techniques are messy and offer little control over inadvertent dripping of the solution into areas where it is undesired.

Alternatively, devices have been developed in an attempt to prevent solution dripping associated with these techniques, and to reduce the time required for application of the antiseptic solution. For example, liquid applicators that hold the liquid in a frangible ampoule and require additional elements to crush the ampoule and release the liquid have been developed. However, existing applicators are often complex to construct and may be difficult or cumbersome to use.

For example, some liquid applicators use a multipart design. By manufacturing the lever separate from the hollow body, different materials may be used to achieve the desired results. For example, typically the hollow body is formed of a flexible, low modulus material such as low density polyethylene. In contrast, the lever is typically formed of a more rigid, higher modulus material such as high density polyethylene or polycarbonate. With such selections, the force applied to lever will be sufficient to compress the hollow body and fracture the ampoule before the lever itself is significantly deformed. However, such a two-part structure is more complex to manufacture.

Other liquid applicators use a one-part design. Here, a lever is integrally formed with the hollow body. The lever includes a hinge, a grip, and a foot. If properly designed, when the grip is depressed, it will rotate about the hinge, causing the foot to compress the hollow body and fracture the ampoule releasing the liquid. The integral design of such applicators is simpler to construct; however, only a single material can be used for the entire construction. In such prior art applicators, rigid, high modulus materials have been chosen to ensure the force applied to lever will be sufficient to compress the hollow body and fracture the ampoule before the lever itself is significantly deformed. This requirement has led to designs that include the use of awkward and less efficient non-cylindrical hollow body designs. Even with such modifications, these applicators may be difficult to operate.

An exemplary liquid applicator according to one embodiment of the present disclosure is illustrated in FIG. 1. Liquid applicator 100 comprises elongated hollow body 110 comprising wall 160. Wall 160 defines chamber 170 having closed end 172 and open end 174. Closed end 172 may be sealed in any of a variety of known ways to inhibit or prevent fluid contained within the chamber from escaping through the closed end. For example, cap 118, which may be press-fit, screwed or otherwise attached, may seal the chamber forming closed end 172.

Open end 174 allows fluid to flow from the hollow body and be applied where desired. In some embodiments, pad 178 may be attached to the open end to control the flow rate and distribution of the fluid. Pad 178 may be formed of any suitable, porous substance including, e.g., sponge, woven and nonwoven materials, screens, meshes and combinations thereof. A wide variety of known materials can be used in the construction of the pad including, e.g., polyester polyurethane and polyester polyether open cell foams.

In some embodiments, such as the one shown in FIG. 1, open end 174 terminates in flange 177, which provides a mating surface for pad 178. In addition, flange 177 may include features such as ribs, holes, and channels to aid in the control and distribution of the flow. The pad can be attached to the flange by known means including, e.g., adhesives and ultrasonic welding.

Ampoule 180 is located within chamber 170. Generally, the ampoule is formed of a frangible material, e.g., glass. Such materials are relatively brittle and will fracture when compressed. This is in contrast to relatively flexible materials that would deform when compressed but which must be punctured to release the liquid inside. In some embodiments, score lines or other features that provide local areas of weakness in the frangible material may be included to control breaking and/or reduce the force required to break the ampoule.

The size and shape of the ampoule is selected to be compatible with the dimensions of the internal chamber and the desired volume of liquid. For example, for use in preparation for a small surgical procedure, the amount of liquid in the ampoule should generally be sufficient to cover an area of, e.g., 10 square centimeters or more. For larger surgical procedures, the amount of liquid in the ampoule may need to be sufficient to cover at least the torso of a large person, e.g., at least about 500-600 square centimeters.

Ampoule 180 contains the liquid to be dispensed. Generally, any liquid can be contained within the ampoule, with the selection of the liquid influencing the selection of the materials used to construct the ampoule and other parts of the applicator, as understood by one of ordinary skill in the art. In some embodiments, the applicator may be particularly useful in dispensing liquids having viscosities at room temperature of less than about 10,000 cps, most preferably less than about 500 cps.

In some embodiments, the ampoule may contain an antiseptic preparation. Examples of suitable antiseptic preparations include those described in U.S. Pat. No. 4,584,192 and those described in U.S. Pat. No. 4,542,012. Other useful fluids include antiseptic preparations, e.g., iodophoric skin tinctures, such as “Duraprep™ Surgical Solution,” commercially available from 3M. In some embodiments, the ampoule be filled with a composition that includes an antimicrobial agent such as iodine, an iodine complex (e.g., iodophors), chlorhexidine, chlorhexidine salts (e.g., chlorhexidine digluconate and chlorhexidine diacetate), or combinations thereof. Other exemplary antimicrobial agents include C2-C5 lower alkyl alcohols, fatty acid monoesters of glycerin and propylene glycol, polymers that include a (C12-C22) hydrophobe and a quaternary ammonium group, polyquaternary amines (e.g., polyhexamethylene biguanide), quaternary ammonium silanes, silver, silver salts (such as silver chloride), silver oxide and silver sulfadiazine, methyl, ethyl, propyl and butyl parabens, octenidene, peroxides (e.g., hydrogen peroxide and benzoyl peroxide), and the like, as well as combinations thereof.

Liquid applicator 100 also comprises lever 130 comprising hinge 132, grip 134, and foot 136. Hinge 132 extends from first location 142, which is integral to hollow body 110, to second location 144. Grip 134 continues the lever from second location 144 to third location 146. Trusses 151 and 155 connect hinge 132 and grip 134 to foot 136. First truss 151 extends from third location 146 to foot 136. Similarly, second truss 155 extends from second location 144 to foot 136.

Lever 130 also includes brace 157 connecting hinge 132 with second truss 155. Brace 157 is integral to hinge 132, intersecting hinge 132 at a location between first location 142 and second location 144. In some embodiments, brace 157 intersects hinge 132 about midway between first location 142 and second location 144, e.g., in some embodiments, brace 157 intersect hinge 132 within +/31 20% of the midpoint, or even within +/−10% of the midpoint of hinge 132, based on the length of the hinge.

Brace 157 is also integral to second truss 155, intersecting second truss 155 between foot 136 and second location 144. In some embodiments, brace 157 intersects second truss 155 about midway between foot 136 and second location 144, e.g., in some embodiments, brace 157 intersect second truss 155 within +/−20% of the midpoint, or even within +/−10% of the midpoint of second truss 155, based on the length of the second truss.

Additional features suitable for use in some embodiments are shown in FIG. 2, which illustrates a cross section of the exemplary applicator 100 of FIG. 1. For example, cap 118, which is press-fit onto hollow body 110, includes optional prongs 119 which conform to the end of ampoule 180 holding in place. Wall 160 includes optional ribs 161 projecting into chamber 170 aiding in the placement and retention of ampoule 180. Hollow body 160 may also include optional stop 175. In some embodiments, when an ampoule is inserted in the chamber, it is seated against the stop helping to position the ampoule relative to the lever. Although not shown, in some embodiments, a screen or other filtering means may be located near open end 174 preventing shards of the crushed ampoule from reaching pad 178.

Hollow body 110 includes handle 116 which can be manually gripped during use. Here, wall 160 has first thickness, T1. In crush region 114, located adjacent foot 136, wall 160 has second thickness, T2, which is less than first thickness, T1. Hollow body 110 may include optional step 111 transitioning between handle 116 and crush region 114.

Generally, first thickness, T1, is selected to provide the desired mechanical integrity and may depend on known factors such as the choice of material and the design of the applicator. For example, for a given material, the wall should be of sufficient thickness to prevent crushing the ampoule when the handle is gripped during normal use. In addition, the thickness should be sufficient to prevent shards of the broken ampoule from penetrating the wall. Generally, first thickness T1 is at least 1 mm, e.g., at least 2 mm. In some embodiments, thickness T1 is no greater than 5 mm, e.g., no greater than 4 mm.

Generally, second thickness, T2, is selected to reduce the force required to deform the wall in crush region 114. As the applicator is often operated with a single hand, the grip is depressed by thumb. Given the wide range of thumb strength for potential operators, it can be desirable to minimize the force required to depress the grip, compress the wall, and fracture the ampoule. However, the second thickness should still be adequate to minimize or prevent unintended crushing and to retain any shards of broken ampoule. Generally, the ratio of T2 over T1 is less than 1. In some embodiments, the ratio of T2 over T1 is no greater than 0.9, no greater than 0.7, or even no greater than 0.5. In some embodiments, the ratio of T2 over T1 is at least 0.2, in some embodiments, at least 0.4.

Generally, the length of crush region 114 should be longer than the length of foot 136. In some embodiments, crush region extends from handle 116 to a location near or at open end 172. In some embodiments, crush region 114 may end at stop 175.

In some embodiments, the crush region may extend throughout the circumference of the applicator. However, in some embodiments, the walls may not be thinned throughout the circumference of the hollow body. For example, in some embodiments, the wall in support region 115 may be thicker than in crush region 114. In some embodiments, the wall in support region 115 may have a third thickness, T3, which is greater than the first thickness, T1. In some embodiments, the ratio of T3 over T1 is at least 1.1, e.g., at least 1.2, or even at least 1.3. Generally, the circumferential width of the crush region should be greater than the width of the foot. In some embodiments, the crush region extends at least +/−30 degrees from the foot, in some embodiments, at least +/−60 degrees, or even +/−90 degrees. Generally the support region would encompass the remaining circumference of the hollow body.

A larger view of exemplary lever 130 is shown in FIG. 3. Hinge 132 connects to and is integral with hollow body 110 at first location 142. The hinge extends from the hollow body at an angle terminating at second location 144 corresponding to the location of second truss 155. Grip 134 continues the lever from second location 144 to third location 146 at a distance H from the hollow body. Foot 136 is connected to, and integral with hollow body 110. First truss 151 extends from third location 146 to foot 136 forming angle A with wall 160. Brace 157 connects hinge 132 and second truss 155.

While there is some flexibility in the design of the lever, the present inventors have discovered certain dimensions which are important to ease of use and functionality. FIG. 4a illustrates a cross section of the lever of FIG. 3, showing its position before crushing ampoule 170. FIG. 4b illustrates a cross section of the lever of FIG. 3, showing its position after crushing ampoule 170 producing shards 171. Angle A and height H should be selected such that when grip 134 is depressed, the travel of foot 136 is sufficient to compress wall 160 in crushing region 114 and fracture ampoule 170 before grip 134 contacts wall 160 in handle region 116. By increasing the angle A, sufficient distance H can be achieved without requiring a grip of unwieldy length. In some embodiments, angle A is greater than 30 degrees, e.g., greater than 40 degrees. If angle A is too steep, however, it may be difficult to actuate the lever. In some embodiments, angle A is no greater than 60 degrees, e.g., no greater than 50 degrees.

Distance, H, will be somewhat dependent on the diameter of the chamber and ampoule, as the foot, and therefore the grip, must be capable of travelling a sufficient distance in order to crush the ampoule. In some embodiments, H is greater than 0.5 times the diameter of the chamber, e.g., at least 1 times the diameter of the chamber, or even at least 1.5 times the diameter of the chamber. In some embodiments, height H is at least 10 mm, e.g., at least 20 mm. In some embodiments, height H is no greater than 40 mm, e.g., no greater than 30 mm.

When grip 134 is depressed with applied force F1, lever 130 operates as a second degree lever applying a crushing force F2 at foot 136. Crushing force F2 can be enhanced relative to applied force F1 by appropriate selection of lengths L1 and L2. L1 is the distance between first location 142 where hinge 132 is connected the wall and the center of foot 136. L2 is the distance from first location 142 to third location 146 at the end of grip 134. Generally, the ratio of F2 over F1 is proportional to the ratio of L2 over L1. In some embodiments, the ratio of L2 over L1 is at least 1.5, e.g., at least 1.8. In some embodiments, the ratio of L2 over L1 is no greater than 3, e.g., no greater than 2.5.

In order to concentrate the crushing force and reduce the applied force required to break ampoule 170, it may be desirable to decrease the size of foot 136. However, if the area of foot 136 is too small, lever 130 may flex to the side when compressed hindering operation. This problem has been reduced in prior art constructions through the use of rigid, high modulus materials. However, alternative approaches are required when flexible, lower modulus materials are used.

Referring to FIGS. 1 and 3, brace 157 assists in stabilizing the lever. In some embodiments, the major axis of brace 157 is substantially parallel to the major axis of elongated hollow body 110. For example, in some embodiments, the major axis of brace 157 and the major axis of elongated hollow body 110 are within +/−20 degrees from parallel, e.g., +/−10 degrees, or even +/−5 degrees from parallel.

In some embodiments, trusses 151 and 155 may merge at a common location at the foot. Alternatively, as shown in FIG. 3, in some embodiments, each of the trusses may connect to foot 136 at spaced-apart locations providing further stability to the lever.

An end view of lever 130 according to some embodiments of the present disclosure is shown in FIG. 5. The top of grip 134 has a first width W1 where it terminates at third location 146. Generally, the top surface of grip 134, including its width, is selected to provide a comfortable and stable base form the application of force to crush the ampoule. In general, the size may be selected to correspond to the expected range of widths of the human thumb. In some embodiments, width W1 is at least 5 mm, e.g., at least 10 mm. In some embodiments, width W1 is no greater than 25 mm, e.g., no greater than 20 mm.

In some embodiments, in order to further concentrate the applied force onto foot 136, first truss 151 may be tapered. That is, the width of first truss 151 may decrease from first width W1 where the truss connects to the grip to second width W2 where the truss connects to foot 136. Generally, the ratio of W2 over W1 is less than 1, e.g., less than 0.8, less than 0.5 or even less than 0.4. The minimum desirable width at foot 136 will be influenced by the desirable stability of the lever, as the narrower the foot the more likely undesirable sidewise flexing may occur. In some embodiments, width W2 is at least 2 mm, e.g., at least 3 mm. In some embodiments, width W2 is no greater than 8 mm, e.g., no greater than 4 mm.

In some embodiments, the width of the second truss is also tapered as the second truss approaches the foot. For example, in some embodiments, the second truss tapers from a third width proximate the second location to a fourth width proximate the foot; wherein the ratio of the fourth width over the third width is less than 1.

Along with its width, the length of foot 136 determines the pressure applied to crush the ampoule, with a smaller foot creating more pressure per unit force applied. As with the width, mechanical robustness and lever stability affect the minimum foot length. However, the addition of the brace connecting the hinge to the second truss provides sufficient additional stability that smaller foot sizes can be used without the instability noted with previous designs. In particular, the brace helps prevent the lever from flexing sidewise when force is applied, despite the use of a smaller foot. As a result of a smaller foot, the applied force can be concentrated onto a smaller crush area, resulting in lower applied forces required to crush the ampule.

In some embodiments, the length of the foot is at least 1 mm, e.g., at least 2 mm. In some embodiments, the length of the foot is no greater than 10 mm, e.g., no greater than 5 mm, or even no greater than 3 mm. In some embodiments, the area of the foot (length multiplied by width) is no greater than 20 square millimeters, e.g., no greater than 10 square millimeters. In some embodiments, the area of the foot is at least 5 square millimeters, e.g., at least 8 square millimeters.

Generally, the levers of the present disclosure include a hinge, a grip, first and second trusses, and a brace. As shown in FIGS. 6a and 6b , in some embodiments, the lever may include additional features. For example, referring to FIG. 6a , liquid applicator 200 includes lever 230 comprising hinge 232, grip 234, and foot 236. Hinge 232 extends from first location 242, which is integral to hollow body 210, to second location 244. Grip 234 continues the lever from second location 244 to third location 246. Trusses 251 and 255 connect hinge 232 and grip 234 to foot 236. First truss 251 extends from third location 246 to foot 236. Similarly, second truss 255 extends from second location 244 to foot 236. Brace 257 connects hinge 232 and second truss 255.

Lever 230 further includes third truss 253 located between first truss 251 and second truss 255. Third truss 253 extends from foot 236 to forth location 248, which is between second location 244 and third location 246. In some embodiments, the third truss provides additional stability to the lever during a crushing operation. In some embodiments, the third truss contributes to concentrating the crushing force onto the foot.

Additional trusses may be included in the lever. For example, referring to FIG. 6b , liquid applicator 300 includes lever 330 comprising hinge 332, grip 334, and foot 336. Hinge 332 extends from first location 342, which is integral to hollow body 310, to second location 344. Grip 334 continues the lever from second location 344 to third location 346. Trusses 351 and 355 connect hinge 332 and grip 334 to foot 336. First truss 351 extends from third location 346 to foot 336. Similarly, second truss 355 extends from second location 344 to foot 336. Brace 357 connects hinge 332 and second truss 355. In some embodiments, lever 330 includes one or more additional trusses, e.g., trusses 352. The locations and angles of such additional trusses may be selected based on desired enhancements such as stability and force concentration.

A wide variety of pads are known, including sponges and fabrics. Generally, such pads have been cylindrical or rectangular in shape with substantially smooth surfaces, i.e., although the surface may have some small scale roughness associated with the material selected, no large scale variations in the thickness of the applicator are present. All such applicators are suitable for use in the various embodiments of the present disclosure. However, in some embodiments, the present inventors have discovered that an undulating pad may provide additional benefits in the uniform application of liquids to surfaces.

Liquid applicators according to the present disclosure were molded from linear low density polyethylene. The required crush force of these unitary structures was compared to the crush force for a commercially available applicator.

Applicators were place in an adjustable block and held at a 45 degree angle with grip portion of the lever in a horizontal position. A pin was mounted vertically in an Instron™ Test Machine such that when the head was lowered the pin would contact the outermost region of the grip. With the applicator held firmly in place, the pin was lowered at 50 millimeters per second and the force required to crush the glass ampoule within the applicator was recorded.

First, a commercial product was tested. The 8635 DuraPrep™ applicator available from 3M Company, St. Paul, Minn., was a two part construction with the hollow body formed from linear low density polyethylene, and a separate lever formed of a rigid polycarbonate. Based on fourteen tests, the average applied force for this commercial product was 48 +/−8 Newton. Commercial experience indicates that this is an acceptable force.

Two applicators according to embodiments of the present disclosure were prepared, as illustrated in FIGS. 1 and 3. These examples were prepared from linear low density polyethylene (flexural modulus of 317 MPa). For both Examples 1 and 2, the foot extended 2.5 mm along the length of the applicator. The width of the foot was 6 4 mm for Example 1, resulting in a foot area of 16 square millimeters. The width of the foot was reduced to 3 8 mm for Example 2, resulting in a foot area of 9.5 square millimeters. Based on fifteen tests for each, the average applied force for was 53 +/−9 Newton for Example 1, and 46 +/−8 Newton for Example 2.

Generally, the applicators of the present disclosure can be made by known methods. In some embodiments, injection molding may be used. A variety of materials may be used to form the applicators. In some embodiments, applicators formed of low flexural modulus materials such as low density polyethylene may be used. For example, in some embodiments, materials having a flexural modulus of no greater than 500 Mpa, e.g., no greater than 400 MPa, or even no greater than 350 MPa may be used.

Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention. 

1. A liquid applicator for applying a liquid to a surface, the applicator comprising: an elongated hollow body comprising a wall defining an internal chamber having a closed end and an open end; wherein the wall comprises a handle region and a crush region and wherein the ratio of thickness of the wall in the crush region over the thickness of the wall in the handle region is less than 1; a first ampoule formed of a frangible material located in the internal chamber proximate the crush region and containing the liquid; a lever integral with the hollow body and comprising a hinge projecting from a first location attached to the hollow body to a second location, a grip extending from the second location to a third location, and a foot integral to the wall adjacent the crush region; wherein the lever comprises a first truss extending from the third location to the foot; a second truss extending from the second location to the foot, and a brace extending from the hinge to the second truss; wherein the width of the first truss is tapered from a first width proximate the third location and a second width proximate foot; wherein the ratio of the second width over the first width is less than
 1. 2. The liquid applicator of claim 1, wherein the width of the second truss is tapered from a third width proximate the second location to a fourth width proximate the foot; wherein the ratio of the fourth width over the third width is less than
 1. 3. The liquid applicator of claim 1, wherein the major axis of the brace and the major axis of the elongated hollow body are within +/−20 degrees from parallel.
 4. The liquid applicator of claim 1, according to any one of the preceding claims, wherein the truss intersects the hinge within +/−20% of the midpoint of the hinge based on the length of the hinge, and wherein the brace intersects the second truss within +/−20% of the midpoint of the second truss based on the length of the second truss.
 5. The liquid applicator of claim 1 according to any one of the preceding claims, wherein the applicator is formed of a material having a flexural modulus of no greater than 500 MPa.
 6. The liquid applicator of claim 1 according to any one of the preceding claims, further comprising a pad connected to the open end of the hollow body. 